An X-ray diffraction analysis method is an analytical technique capable of identifying a crystalline substance contained in a material or evaluating a crystal structure. The X-ray diffraction analysis method that uses a point detector, which cannot identify a position of an X-ray incident on a detection surface, needs an appropriate slit to measure a diffracted X-ray from a sample and acquire an X-ray diffraction profile representing an X-ray diffraction intensity corresponding to a diffraction angle.
In recent years, unlike the analysis method that uses the point detector, an analysis method in which a two-dimensional detection circuit capable of identifying a position of an X-ray incident on a detection surface is used is being used to acquire an X-ray diffraction profile. In an X-ray diffraction analysis apparatus equipped with such a two-dimensional detection circuit, since the two-dimensional detection circuit is usually used for the purpose of improving the quality of data and speeding up the measurement, it is common that a sample is rotated or rocked to average sample orientations to obtain a diffracted X-ray image. In this case, the obtained diffracted X-ray image has a ring shape, so-called Debye ring, in which all diffraction spots are connected.
There has also been proposed an X-ray diffraction analysis method which aims at the rapid identification and evaluation of a crystal phase (see, e.g., Japanese Laid-Open Patent Publication No. 2013-068555). In this method, while performing the X-ray diffraction measurement, a peak position and an integrated intensity of a diffracted X-rays are obtained, the number of X-ray diffraction peaks is counted, and an analysis processing of identification and quantification of a crystal phase is started when the counted number of peaks reaches a predetermined value. Therefore, it is possible to analyze a material more quickly than before. In this method, when a crystal phase contained in a material is known to some extent and is expected that the range thereof is limited before the measurements, it is possible to analyze the material promptly because analysis is performed on a partially measured X-ray diffraction profile while performing the measurement.
Related Techniques are disclosed in, for example, Japanese Laid-Open Patent Publication No. 2013-068555.